Introduction

Network covert channels (network steganographic hiding methods) are used to hide communication inside network communications. Within the last
decades, various techniques for covert channels arose. We surveyed and analyzed 130+ techniques developed between 1987 and 2015 and show that these techniques can be reduced to only few so-called patterns (Wendzel et al., 2015 (preprint); Wendzel et al., 2016; Mazurczyk et al., 2016). Patterns are simple and abstract descriptions of a hiding technique's core idea.

We found that the majority (83%) of the evaluated hiding techniques can be categorized in only six different patterns; 63% of all hiding techniques can even by categorized in only three different patterns (Wendzel et al., 2016). This shows that most
of the techniques we surveyed are very similar.

This website provides our pattern catalog to the scientific community and allows discussion and extension of the catalog. Our pattern catalog will serve as a basis for future covert channel novelty evaluation. In addition, our approach lays the foundation for pattern-based countermeasures: While
many current countermeasures were developed for specific channels, a pattern-oriented approach allows to
apply one countermeasure to multiple channels. Hence, future countermeasure development can focus on
patterns, and the development of real-world protection against covert channels is greatly simplified.

What is the basis for this catalog?
We described the details of the pattern-based approach in the following articles, especially (Wendzel et al., 2015), which also provides various additional ideas related to hiding patterns, such as pattern variation and pattern hopping.